The number of accidents fell significantly last year at the first suburban intersections to be patrolled with cameras, but state officials caution that a change in reporting requirements makes a year-to-year comparison suspect.
Overall, the number of collisions at the 14 suburban intersections in 2009 dropped 36 percent from the number in 2008. Collisions decreased at 11 of the 14, according to the Illinois Department of Transportation.
Accidents increased at two intersections and showed no change at another. But the state raised the minimum level to report a property damage accident from $500 to $1,500, reducing the number of reported crashes statewide by 28 percent and potentially skewing the results, officials said.
At the same time, the number of accidents in which someone was injured, a figure unaffected by the reporting change, fell to 30 from 39 at the same sites last year, according to IDOT statistics.
The most serious type of accidents the cameras are meant to deter are broadside collisions, , when a car runs a red light and hits a crossing vehicle. The number of those collisions dropped to eight from nine.
Rear-end collisions, which sometimes increase after cameras are installed, fell 32 percent, the statistics show.
Five pedestrians were struck at the intersections in 2009; none had been hit in 2008.
A Tribune analysis last year of the same intersections found that in 2008, the number of crashes rose — in some cases, significantly — at half of them. The number of crashes fell at five of those intersections after cameras went in, while two showed little change.
